Pneumatically controlled dispensing system

ABSTRACT

The invention provides a pneumatically controlled dispensing system wherein the strokes of an air-operated fill pump, which is adapted to deliver a predetermined amount of fill material on each directional stroke, are sensed and a flow valve at a fill station is thereby controlled, which dispensing system comprises: (a) air-operated signal means for sensing each stroke of said pump and for producing an air pulse corresponding to each air pulse corresponding to each said stroke; (b) air-operated counter means for counting each air pulse produced by said signal means for producing an air pressure response signal after receiving a predetermined number of said air pulses; (c) flow valve means movable between a first and a second position for directing the flow of fill material delivered thereto from said pump between a first and a second outlet line; and (d) actuator means operated by said response signal of said counter means for moving said valve means between said first and second positions.

United States Patent 3,065,880 11/1962 Brown Inventor Wilfred L. MuirMaplewood, Minn.

Appl. No. 33,627

Filed May 1, 1970 Patented Oct. 19, 1971 Assignee Minnesota Mining andManufacturing Company St. Paul, Minn.

References Cited UNITED STATES PATENTS 3,489,155 1/1970 LovelessABSTRACT: The invention provides a pneumatically controlled dispensingsystem wherein the strokes of an airoperated fill pump, which is adaptedto deliver a predetermined amount of fill material on each directionalstroke, are sensed and a flow valve at a fill station is therebycontrolled, which dispensing system comprises: (a) air-operated signalmeans for sensing each stroke of said pump and for producing an airpulse corresponding to each air pulse corresponding to each said stroke;(b) air-operated counter means for counting each air pulse produced bysaid signal means for producing an air pressure response signal afterreceiving a predetermined number of said air pulses; (c) flow valvemeans movable between a first and a second position for directing theflow of fill material delivered thereto from said pump between a firstand a second outlet line; and (d) actuator means operated by saidresponse signal of said counter means for moving said valve meansbetween said first and second positions.

PNEUMATICALLY CONTROLLED DISPENSING SYSTEM This invention relates to aninexpensive pneumatically controlled dispensing system in which thestrokes of an airoperated fill pump are sensed and thereafterhigh-pressure air pulses are produced in such a manner that they controlthe switching of a follow valve to allow continuous filling ofcontainers by the air-operated fill pump.

BACKGROUND OF THE INVENTION It is common for numerous types of viscousmaterials to be sold in cartridge form as well as in other smallcontainers. For example, adhesives, caulking compounds, greases, etc.are often sold in a cartridge form after being filled by themanufacturer. I-Ieretofore, the filling of cartridges with such viscousmaterials has beenaccomplished either with expensive automatic fillingmachines or by simple pneumatic filling systems which are manuallycontrolled.

Since many of these fill materials contain some amount of solvent, thesystem used for dispensing the fill material into cartridges must notgenerate any sparks so that fire hazards are reduced to a minimum.Therefore, whenever any type of electrical systems are used for thedispensing of fill material or for controlling the filling of cartridgesand containers, elaborate precautions, such as explosion-proof housings,must be used. Consequently, the cost of electrically controlled fillingsystems may become prohibitive.

Some have used simple pneumatic filling systems. and since the system ispneumatic, no elaborate precautions need be taken in order to prevent afire hazard. However, such pneumatic filling systems are not automatic,but rather require manual control of valves whereby the filling systemis shutdown when one cartridge or container is full in order to replacethe full cartridge or container with an empty one. As a result, manualfilling systems are slow. Such filling systems are also inefficientbecause it is difficult to accurately control the exact amount of fillmaterial dispensed into a container.

SUMMARY OF THE INVENTION The invention provides an inexpensive pneumaticcontrol system for use with an air-operated fill pump wherein thecontrol system senses the number of strokes of the air fill pump andthereby automatically controls an actuator for a flow valve in a fillline so that when one cartridge or container at a first fill linereceives a predetermined amount of fill material the flow valve isactuated so as to direct the follow of fill material to an emptycartridge or container at a second fill line which will be filledwithout stopping the operation of the said fill pump.

The dispensing of fill material is, therefore, automatic becausecartridges and other containers may be filled on a continuous basis. Theoperation of the filling system requires only that filled cartridges orcontainers be replaced with empty containers while the system is fillingan empty container. There is no need to stop the fiow of fill materialfrom the pump during the operation of the system because the fiow valveis actuated automatically to fill another container when one containeris full. Thus, cartridges and containers may be filled at a rate whichis as fast as the fill pump can deliver the fill material. Because theentire filling system, including the control system, is pneumatic, nofire hazards are presented.

Thus, there is provided an inexpensive, automatic dispensing system forfilling cartridges or other containers with fill material which maycontain solvent. The system may be used where completely automaticsystems are too expensive or cumbersome, and it may be used in areaswhere fire hazards are presented due to the presence of solvents. Thesystem is also quite efficient in that a metered, predetermined amountof fill materialis delivered to each container, and the automaticswitching of fill material from one container to another minimizesspills and waste. The system is capable of controlling the amount offill material delivered to each container within an accuracy of about 99percent.

strokes of an air-operated fill pump, which is adapted to deliver apredetermined amount of fill material on each directional stroke, aresensed and a flow valve at a fill station is thereby controlled todirect Xa predetermined amount of fill material seriatim to a first anda second outlet line. The dispensing system comprises: (air-operatedsignal means for sensing each stroke of said pump and for producinganair pulse corresponding to each said stroke; (b) a first and a secondair-operated counter means for counting each said air pulse produced bysaid signal means, wherein said first counter produces a first airpressure response signal after receiving a predetermined number of saidair pulses and said second counter is adapted to produce a second airpressure response signal spaced from said first air pressure responsesignal by one-half the number of said predetermined number of said airpulses; (c) flow valve means movable between a first and a secondposition for directing the flow of fill material delivered from saidpump between a first and a second outlet line; and (d) actuator meansoperated by said first and second air pressure response signals of saidfirst and second counter means for moving said valve means between saidfirst and second positions.

In another embodiment there is provided a pneumatically controlleddispensing system wherein the strokes of an airoperated fill pump, whichis adapted to deliver a predetermined amount of fill material on eachdirectional stroke, are sensed and a flow valve at a fill station isthereby controlled to direct a predetermined amount of fill materialseriatim to a first and a second outlet line. The dispensing systemcomprises: (a) air-operated signal means for sensing each stroke of saidpump and for producing an air pulse corresponding to each said stroke,(b) air-operated counter means for counting each said air pulse producedby said signal means and for producing an air pressure response signalafter receiving a predetermined number of said air pulses, (c) flowvalve means movable between a first and a second position for directingthe flow of fill material delivered from said pump between a first and asecond outlet line, and (d) actuator means operated by said responsesignal of said counter means for moving said valve means between saidfirst and second positions.

The invention will be described in more detail herein after withreference to the accompanying drawings wherein like reference charactersrefer to the same part throughout the several views and in which:

FIG. 1 shows a schematic diagram of one embodiment of the invention;

FIG. 2 shows a schematic diagram of another embodiment of the invention;and

FIG. 3 shows a schematic diagram of still another embodiment of theinvention.

Referring first to FIG. 1, there is shown generally a schematic diagramof a pneumatic control system 10 connected to an air-operated fill pumpof the type which uses an air cylinder motor which is alternately drivenin two directions by air pressure to effect the pumping action of thepump. The pneumatic control system receives an air signal from theair-operated fill pump 12 through air line 11. The air signalso receivedby the control system corresponds to onedirectional stroke of said fillpump. Said air signal may be simply taken from the air exhaust of themotor on the fill pump or it may be produced by a separate air valve,e.g., the pump could be adapted to trigger an air valve on eachdirectional stroke. The air signal may be amplified, or increased inpressure, bypassing it through a enough force to cause the valve in thehigh pressure airline to open momentarily. A typical such valve is onesold by Humphrey Products under model number 250AL. The valve 13therefore produces an air pulse of relatively high, i.e., 40 -60 p.s.i.,air pressure corresponding to each air signal received from the pump 12.

The reason for passing the air signal from the fill pump through valve13 and increasing its pressure to 40-60 p.s.i. is because the particularcounters described below will not register an air pulse whose pressureis below 40 p.s.i. When using counters which will register air pulses ofless than 40 p.s.i., or when operating the fill pump at a pressure above40 p.s.i., it is not necessary to amplify the air signal received fromthe fill pump in order to have said signal or pulse registered by thecounter.

Air line 16 transports this high pressure air pulse, whether it isproduced by valve 13 or is taken directly from the pump, to each of twocounters 18 and 20. Each of the two counters is connected to a highpressure (60-125 p.s.i.) air supply line 17. Each of the countersregisters each said air pulse delivered to it and accumulates the countinformation. Typical pneumatic counters useful in the practice of theinvention are those sold by Humphrey Products under model number SAC 24.Upon the receipt by a counter of the last of a predetermined number ofair pulses, the counter opens an internal valve which momentarilyconnects air line 17 to an exit line; the exit line for counter 18 isline 19, and the exit line for counter 20 is line 22. As soon as acounter supplies a high-pressure air signal through the exit line, thecounter resets itself for another cycle.

The two counters are staggered (offset) so that one counter trips oropens the high-pressure air line 17 after receiving a predeterminednumber of air pulses (measured by twice the number of strokes of thefill pump which are needed to fill a container) at a time when the othercounter has received only one-half the required amount of saidpredetermined number of air pulses. Generally, the result of using thetwo counters in the manner just described is that the first countersupplies an air pressure signal at the same moment that one containerhas received a predetermined amount of fill material from the fill pump.This air pressure signal controls the switching of a flow valve from afirst position to a a second position so that fill material coming fromthe pump will be directed toward a second container. When this secondcontainer receives a predetermined amount of fill material, the secondcounter will supply an air pressure signal which will control theswitching of the flow valve back to its first position. A more specificdescription follows.

When an air pressure signal is sent by counter 18 through exit line 19,it is received at a pilot valve 24 which may be any of those pilotvalves well known in the art. Valve 24 is fed also by the exit line 22from counter 20, and is also fed by highpressure air (60l25 p.s.i.)through line 17. Said air pressure signal is received by one end ofvalve 24 through air line 19 and actuates valve 24 so as to allow thehigh-pressure air coming from line 17 to pass through valve 24 out theexit line 26. This high-pressure air is received by actuator valve 36 atend 32 and actuates the three-way ball valve 38 so that fill materialcoming from the fill pump is directed toward outlet line 40. Typicalactuator valves which are useful in the practice of the invention arethose sold by Contromatics Corporation in their 4,000 Series. Usefulthree-way ball valves are those available from Contromatics in variousmodels and sizes. When valve 24 receives a high air pressure signal fromcounter 20 through line 22, the valve 24 is actuated so as to allow thehigh pressure air from line 17 to pass through valve 24 to the exit line28. This high-pressure air is received by actuator valve 36 at end 34and actuates the three-way ball valve 38 so that fill material isdirected toward outlet line 42.

Each counter is set so as to send an air pressure signal to an actuatorvalve after receiving a predetermined number of air pulses from the fillpump. The predetermined number of air pulses is actually equal to twicethe number of directional strokes of said pump which are required tofill a container, but because the counters are offset, the overalleffect is that one counter controls the switching of the flow valve toone outlet line and the other counter controls the switching of the flowvalve to the other outlet line, and the flow valve is switched each timea container receives a predetermined amount of fill material. Thecounters thus are alternately controlling the flow valve.

The air-operated fill pump from which the air signals are received bythe control system is a pump which is adapted to deliver a predeterminedamount of fill material per stroke. A common type of fill pump is onesold under the trade designation Graco which is made by the Gray Co.Xand which is fitted with a stroke adjustor. A common such strokeadjustor is made by A. G. Barstow Company under model number 1,675. Apreferred pump is a model 10 l Bulldog, useful for pumping very viscousmaterial. The stroke adjustor allows one to predeterrnine the amount offill material delivered on each directional stroke of the fill pump. Theamount of fill material delivered with each directional stroke of theair-operated pump is important because the counters must be set so as toproduce a high air pressure signal upon the receipt of a predeterminednumber of air signals. The high air pressure signals produced by thecounters eventually determine when a flow valve is to be switched fromone container to another so it is imperative that the counter producethis high air pressure signal at the required time so that the flow offill material is directed from a full container to an empty containerwithout stopping the operation of the air fill pump.

Referring next to FIG. 2 there is shown a schematic view of a pneumaticcontrol system, useful when the air fill pump is operated with airpressure above that required to have the counters register air signals,which receives an air signal from an air fill pump 12 through air line11. The air signal so received may correspond to one or two directionalstrokes of said air fill pump. Air line 11 transports said air signal toeach of the counters l8 and 20 where it is registered and the countinformation accumulated. One of said counters is staggered, or offset,from the other in the manner previously described. When counter 18receives the predetermined number of counts it opens a high air pressureline for an instant and allows a high air pressure signal to exitthrough air line 19 to one end 32 of an actuator valve 36. At this pointcounter 20 is set so that it must still receive one-half of thepredetermined number of counts in order for it to be activated. The highair pressure signal received by the actuator valve 36 at end 32 actuatesthe valve 36 so as to switch a three-way ball valve 38 so that fillmaterial entering the three-way ball valve through fill line 30 isdirected toward outlet line 40. When counter 20 receives the requiredpredetermined number of counts it will produce a high air pressuresignal which will exit through air line 22 and will be received atactuator valve 36 at end 34. The high air pressure signal will actuatethe valve 36 causing it to turn the three-way ball valve 38 so as todirect the flow of fill material from fill line 30 to outlet 42. Theactuator valve 36 switches the three-way valve 38 very quickly so thatthere is no need to stop the pump when it is desired to switch theoutlet of fill material from one container to another.

FIG. 3 shows a schematic view of a pneumatic control system utilizingonly one counter. The counter 18 is connected to air line 11 whichtransports an air pulse or signal from an air-operated pump or motor.The counter is also connected to a high air pressure line 17. Thecounter is also con nected to a high air pressure line 17. The counterhas an air exit line 19 which goes to a first pilot valve 44. As thecounter receives the air signals through air line 11, it accumulates thecount information until the required predetermined number of air signalsis received. When the last of the predetermined number of signals isreceived by the counter, it allows a short pulse of constant high airpressure (60-125 p.s.i.) to exit from the counter through air line 19 tothe first pilot valve 44. At this point the pilot valve is open so thatthe high air pressure pulse may pass through the valve into air line 46.Air line 46 carries this high air pressure pulse to a second pilot valve18 where it is received at one end 47 of this pilot valve. Said pilotvalve is also fed by a constant high air pressure (60-125 p.s.i.) line17. The high air pressure pulse received by said valve at end 47actuates said valve so as to Xallow a constant high air pressure fromline 1'7 to pass through said valve into air line Sll which transportssaid constant high air pressure to an actuator valve 36 where it isreceived at one end 32 of said actuator valve Said air line 50 isconnected to a recycle air line 51. Said recycle air line 511 alsoreceives part of said constant high air pressure and transports it to apneumatic time delay valve 52 which may be any of those well known inthe art. Said time delay valve will not allow the air pressure to passthrough this valve immediately, but after a moment it will open andallow a constant high air pressure to pass through air line 54 to oneend 43 of said first pilot valve M. In this manner, the high airpressure has been received by actuator valve 36 so as to actuate athree-way valve 38 which in turn directs the flow of fill materialbetween a first and a second outlet, and after the actuator valve 36 hasbeen actuated, the high air pressure has been received by said firstpilot valve 44 so as to actuate said valve. Thus, the high air pressureline has first switched or actuated the three-way ball valve 38 and thenhas actuated said first pilot valve 44 so that when the counter ltlcounts the required number of air signals, and allows a pulse of highair pressure to exit through air line 19 to said first pilot valve, thefirst pilot valve will be open so as to allow the short high airpressure pulse to pass through said valve into air line 55 which willtransport this pulse to said second pilot valve 4%. The second pilotvalve 48 receives this high air pressure pulse at end 56 and is therebyactuated so as to allow constant high air pressure to pass from line 17through said pilot valve into air exit line 58. Air line 58 transportssaid constant high air pres sure to actuator valve 36 where it isreceived at end 1%. The actuator valve 36 is thereby actuated and causesthe three-way valve 3% to turn and direct the flow of fill material tothe other of said outlet lines. Air line 59 is connected to air line 58so that when the high air pressure passes through line 58 a portion ofit is received by air line 59 which transports it to a second time delayvalve 60. Said time delay valve, after a moment, will allow saidconstant high air pressure to pass into air line 62 where it willeventually be received by said first pilot valve at end 64. In thismanner, said first pilot valve is actuated and is set so as to receiveanother pulse of high air pressure from counter 18 through air line 19so that the cycle can be carried through again.

As an alternative to controlling the switching of a three-way ball valvewith the air pressure pulses from the counters, it is possible to havethese air pressure pulses control other types of dispensing or flowvalves. For example, any valve which is movable between a first positionand a second position may be controlled with the pneumatic controlsystem of the invention. For example, particularly useful dispensing orflow valves for some applications are those available from A. G. BarstowCompany under the model Hi-Volume 3/41 inch Dispensing Valve. Two ofthese dispensing or flow valves may be operated and controlled inaccordance with the control system of the invention so that continuousfilling of containers is achieved without stopping the operation of theair-operated fill pump by connecting the dispensing valves in a parallelarrangement whereby the first dispensing valve delivers fill materialwhile the second valve is closed, and then the second dispensing valvedelivers fill material while the first valve is closed. The operation isthus an alternate dispensing of material between two valves on acontinuous basis. Furthermore, other flow valves may also be connectedin a parallel arrangement so that two or more delivers valves arecontrolled by the same air pressure signal. dispensing parallel pressureThe pneumatic control system of the invention is also useful forcontrolling the dispensing of liquids, including solvents, in additionto viscous solvent-containing materials up to a viscosity of 30,000poise. The important aspect is that an airoperated pump or other air-perated device deliver a predetermined amount of materra on eachdirectional stroke so that the counters may be adapted to receive anumber of air pulses from said air-operated device in a directcorrelation with the number of strokes of said air-operated device.

What is claimed is:

1. A pneumatically controlled dispensing system wherein the strokes ofan air-operated fill pump, which is adapted to deliver a predeterminedamount of fill material on each directional stroke, are sensed and aflow valve at a fill station is thereby controlled, which dispensingsystem comprises: (a) air-operated signal means for sensing each strokeof said pump and for producing an air pulse corresponding to each saidstroke; (b) air-operated counter means for counting each said air pulseproduced by said signal an air pressure response signal after receivinga predetermined number of said air pulses; (0) flow valve means movablebetween a first and a second position for directing the flow of fillmaterial delivered thereto from said pump between a first and a secondoutlet line; and (d) actuator means operated by said response signal ofsaid counter means means for moving said valve means between said firstand second positions.

2. A pneumatically controlled dispensing system in accordance with claim3 wherein said flow valve means is a three-way bass valve.

3. A pneumatically controlled dispensing system wherein the strokes ofan air-operated fill pump, which is adapted to deliver a predeterminedamount of fill material on each directional stroke, are sensed and aflow valve at a fill station is thereby controlled, which dispensingsystem comprises: (a) air-operated signal means for sensing each strokeof said pump and for producing an air pulse corresponding to each saidstroke; (b) a first and a second air-operated counter means for countingeach said air pulse produced by said signal means, wherein said firstcounter produces a first air pressure response signal after receiving apredetermined number of said air pulses and said second counter isadapted to produce a second air pressure response signal spaced fromsaid first air pressure response signal by one'half the number of saidpredetermined number of said air pulses; (c) flow valve means movablebetween a first and a second position for directing the flow of fillmaterial delivered thereto from said pump between a first and a secondoutlet line, and; (d) actuator means operated by said first and secondair pressure response signals of said first and second counter means formoving said valve means between said first and and second positions.

4. A pneumatically controlled dispensing system in accordance with claiml wherein said flow valve means is a three-way ball valve.

5. A pneumatically controlled dispensing system wherein the strokes ofan air-operated fill pump, which is adapted to deliver a predeterminedamount of fill material on each directional stroke, are sensed and aflow valve at a fill station is thereby controlled, which dispensingsystem comprises: (a) a first and a second air-operated counter meansfor sensing and counting each directional stroke of said pump, whereinsaid pump is operated with air having a pressure greater than requiredto operated said first and second counter means, and wherein said firstcounter produces a first air pressure response signal after sensing apredetermined number of said directional strokes and said second countermeans is adapted to produce a second air pressure response signal spacedfrom said first air pressure response signal by one-half the number ofsaid predetermined number of said directional strokes; (b) flow valvemeans movable between a first and a second position for directing theflow of fill material delivered thereto from said pump between a firstand a second outlet line. and (c) actuator means operated by said firstand second air pressure response signals of said first and secondcounter means for moving said valve means between said first and secondpositions.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No.3,613,951 Dated October 1Q 1971 Inventor(s) Wilfred L. Muir It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the Abstract, lines .8 --.9 delete the phrase "air pulsecorresponding to each"; Column 2, line 8, delete "g" and insert --(a)--;Column 4, line 13, delete 'X"; Column 4, lines 65-66, delete the phrase"The counter is also connected to a high air pressure line 1?." Column5, line 5, delete "X";

line 67 delete "delivers" and insert flowline 66, delete "dispensingparallel ressure Column 6, line 15, after "signal" and before "an'insert -means and for producing; line 25, delete "bass" and insert--ball--.

Signed and sealed this 11th day of April 1972.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTI'SCHALK Attesting Officer Commissionerof Patents RM PO-1050 (10-69) uscoMM-oc scan-P59 LLS GOV [RNHENYPRINTING OFFICE: I'll 0-lll-Sll

1. A pneumatically controlled dispensing system wherein the strokes ofan air-operated fill pump, which is adapted to deliver a predeterminedamount of fill material on each directional stroke, are sensed and aflow valve at a fill station is thereby controlled, which dispensingsystem comprises: (a) air-operated signal means for sensing each strokeof said pump and for producing an air pulse corresponding to each saidstroke; (b) Air-operated counter means for counting each said air pulseproduced by said signal an air pressure response signal after receivinga predetermined number of said air pulses; (c) flow valve means movablebetween a first and a second position for directing the flow of fillmaterial delivered thereto from said pump between a first and a secondoutlet line; and (d) actuator means operated by said response signal ofsaid counter means means for moving said valve means between said firstand second positions.
 2. A pneumatically controlled dispensing system inaccordance with claim 3 wherein said flow valve means is a three-waybass valve.
 3. A pneumatically controlled dispensing system wherein thestrokes of an air-operated fill pump, which is adapted to deliver apredetermined amount of fill material on each directional stroke, aresensed and a flow valve at a fill station is thereby controlled, whichdispensing system comprises: (a) air-operated signal means for sensingeach stroke of said pump and for producing an air pulse corresponding toeach said stroke; (b) a first and a second air-operated counter meansfor counting each said air pulse produced by said signal means, whereinsaid first counter produces a first air pressure response signal afterreceiving a predetermined number of said air pulses and said secondcounter is adapted to produce a second air pressure response signalspaced from said first air pressure response signal by one-half thenumber of said predetermined number of said air pulses; (c) flow valvemeans movable between a first and a second position for directing theflow of fill material delivered thereto from said pump between a firstand a second outlet line, and; (d) actuator means operated by said firstand second air pressure response signals of said first and secondcounter means for moving said valve means between said first and andsecond positions.
 4. A pneumatically controlled dispensing system inaccordance with claim 1 wherein said flow valve means is a three-wayball valve.
 5. A pneumatically controlled dispensing system wherein thestrokes of an air-operated fill pump, which is adapted to deliver apredetermined amount of fill material on each directional stroke, aresensed and a flow valve at a fill station is thereby controlled, whichdispensing system comprises: (a) a first and a second air-operatedcounter means for sensing and counting each directional stroke of saidpump, wherein said pump is operated with air having a pressure greaterthan required to operated said first and second counter means, andwherein said first counter produces a first air pressure response signalafter sensing a predetermined number of said directional strokes andsaid second counter means is adapted to produce a second air pressureresponse signal spaced from said first air pressure response signal byone-half the number of said predetermined number of said directionalstrokes; (b) flow valve means movable between a first and a secondposition for directing the flow of fill material delivered thereto fromsaid pump between a first and a second outlet line. and (c) actuatormeans operated by said first and second air pressure response signals ofsaid first and second counter means for moving said valve means betweensaid first and second positions.